An electric dipole of moment ' $P$ ' is placed in the position of stable equilibrium in a uniform el

Question

An electric dipole of moment ' $P$ ' is placed in the position of stable equilibrium in a uniform electric field of intensity ' E '. If it is rotated through angle $	heta$ the potential energy of the dipole in its final position is\

Professor PC Thomas Classes · Answer

Potential energy $\mathrm{U}=$ work done in rotating. $$ \begin{aligned} & =\mathrm{PE}\left(\cos 	heta_{1}-\cos 	heta_{2}ight) \ & =\mathrm{PE}(\cos 0-\cos 	heta) \ & =\mathrm{PE}(1-\cos 	heta) \ & =\mathrm{PE} 	imes 2 \sin ^{2}\left(\frac{	heta}{2}ight) \end{aligned} $$